test__benchmarks.py: better error reporting

greentest/test__benchmarks.py

@@ -4,11 +4,13 @@ import mysubprocess as subprocess
 import time
 
 
+TIMEOUT = 10
+
 def system(command):
     p = subprocess.Popen(command, shell=True)
     try:
         start = time.time()
-        while time.time() < start + 10 and p.poll() is None:
+        while time.time() < start + TIMEOUT and p.poll() is None:
             time.sleep(0.1)
         if p.poll() is None:
             p.kill()
@@ -24,20 +26,21 @@ modules = set()
 for path in glob.glob('bench_*.py'):
     modules.add(path)
 
-assert modules
-
-error = 0
-
 if __name__ == '__main__':
+    assert modules
+
+    errors = []
 
     for path in modules:
-        print (path)
+        sys.stderr.write(path + '\n')
         sys.stdout.flush()
-        res = system('%s %s all' % (sys.executable, path))
+        command = '%s %s all' % (sys.executable, path)
+        res = system(command)
         if res:
-            error = 1
-            print ('%s %s' % (path, 'failed'))
-        print ('-----')
+            error = '%r failed with code %s' % (command, res)
+            sys.stderr.write(error + '\n')
+            errors.append(error)
+        sys.stderr.write('-----\n\n')
 
-    if error:
-        sys.exit(1)
+    if errors:
+        sys.exit('\n'.join(errors))